You will run up hart against EU laws. It is basically illegal to sell stuff without a specific basic warranty in the EU. Apple lost millions over this. Additional warranties are of course welcome.

The second problem is the paperwork related to CE . This might entail additional certificates from third parties regarding electrical safety. (For me, CE resulted in serious tests of each individual device we sold. But you don't have 230V AC inside.)

German distributors will definitely ask about these two points.

The next biggy is importing into the EU. UKs "maybe,maybe-not,maybe-soon" exit means you have to deal with EU import taxes at some point. That will cause problems and distributors want stable and steady supply guaranties. I don't think they want a new startup from UK right now.

Most of these things disappear if you sell self assembly sets privatly (like Jens does)... ask him directly.

Outright claiming your stuff is better then the device developed by the local resident electrical guru and only successful startup was also a not-so-bright idea. It might be the case, but do a test first.